The present invention relates, in general, to a house for raising livestock and, in particular, an improved house for raising domestic animals and poultry for market, at an improved efficiency.
The term "livestock" is herein employed to mean both domestic animals and fowls, particularly those bred and raised in a great number of individuals for the meat market, for example such as hogs and chickens typically.
In the case of fowl raising, it is required that the young of fowl are raised to exceed a prescribed value of their average weight within a shorter period of time, at a reduced rate of their accidental death and with their inter-individual variation for example in weight suppressed as much as possible, as well as their consumption of feed.
Whereas the method of fowl farming and houses for the practice thereof have been variously developed since long before, in recent years in particular it has grown to be of public interest to raise chickens for the flesh market in a certain great number of individuals and under certain limited conditions relating to the period of time and space for raising, and so forth.
The present invention, too, is directed in its objects to minimization of the consumption of feed, shortening of the time required for sufficient growth of chickens, suppression of variation in the degree and manner of growth of individual chickens and so forth, through reliance on a unique system of raising.
As a desirable house for therein raising a great number of chickens at a same time, a structure is known, which broadly comprises a roof, side walls, ceiling and floor and which essentially is closed. With ordinary open-structure constructions having a constantly open window or windows, various difficulties are encountered. For example, it is difficult with them to control the room temperature of to be even or constant within the house. Also, the lightness within the house can change to a great extent as the time of the day changes, and particularly during the daytime, it is so bright within the house that chickens can be stimulated to take exercise, disadvantageous to the interests of the livestock farmers in a sooner growth of chickens. A further difficulty with those houses having open windows resides in that they can easily permit entry or intrusion of wild animals such as rats, weasels or the like, foreign enemies to chickens. Thus, those constructions are not suitable for the large scale poultry farming or mass raising of poultry under reference.
Then, in the case of a construction having a substantially closed structure, ventilation, temperature control, lighting and so forth are all operated artificially, so that it is feasible to adjust various conditions to optimum ones for poultry raising.
In order to develop an efficient system for promoting the growth of chickens, the poultryman should necessarily have a good knowledge of the nature of poultry, and in this respect, the present inventors have conducted a number of experiments to obtain a variety of data and exerted efforts to determine on the basis of the data obtained optimum conditions under which the growth of poultry can be most efficiently promoted. According to the results obtained from the above, it has been found for example that in accordance with a change in the weekly age of chickens, an optimum room temperature can change: When chickens are younger, the room temperature is required to be higher, which preferably is to be increasingly lower as the chickens grow older. Over a series of experiments in which the floor temperature was variously altered, it also was discovered that poultry have ability to feel the temperature through the plantar skin and behavior to move to a place on the floor having a temperature suited to respective individuals.
It has hitherto been known to keep warm the floor of the chicken-raising house, and in practice it is generally practised to provide a hot water piping beneath the floor and circulate temperature controlled water through the piping. However, with such system of warming the floor, it is unavoidable that a considerable temperature difference occurs in different portions on the floor depending on whether or not the hot-water circulation piping is nearby located, or whether the particular portion lies near the supply end or the discharge end of the piping. Also, likely in this case is choking of the pipe, causative of a serious difference in the temperature distribution. In an extreme instance of variation in the temperature distribution, a great number of chickens would altogether rush to a limited area on the floor where an optimum temperature condition is maintained. Even if death of chickens due to mutual pressing or suffocation, which often occurs then, may be avoided, chickens tend to gather in a line or row along a portion of the embeded hot-water circulation line about which an optimum temperature condition is present, and exert mutual pushing to disadvantageously consume their energy and accordingly undergo a delay in their growth or raise the rate of their demand for feed, that is, the rate of an amount (Kg) of feed to an increase by 1 Kg in the weight of the chicken. A further problem in case of an irregular temperature distribution resides in that fowl droppings are permitted to undergo desication at varied speeds about different portions on the floor, whereby putrefactive fermentation can be caused in a shorter period of time. Also, in anticipation of heat loss during circulation, hot water may be supplied as overheated, and it then is likely that a concrete floor of the house undergoes cracking, resulting in the generation of a hygienically undesirable condition about the house. If the hot water supply or circulation is broken during wintertime, further, likeliness exists that the water remaining in the pipe becomes frozen to destroy the pipe.
Thus, how to evenly control the temperature distribution substantially throughout the whole floor area has long been one of problems awaiting solution in the field of mass-raising of poultry.
In this connection, there has been a proposal made, according to which hot air is sent into the chicken-raising house from the ceiling or side walls thereof. A difficulty indicated of this proposed system for warming the chicken raising room derives from the fact that the system requires fans for forcibly circulating the atmosphere within the room in order to have evenly warmed the atmosphere close to the floor surface in which the chickens live and grow. In this case, to provide fans of a large size within the room or house accompanies generation of noise and vibration, which give rise to stress to chickens being raised and disturbance to their growth as later to be described in greater detail. Also, with circulation of hot air alone, the floor temperature can hardly sufficiently be elevated in comparison to the temperature of the atmosphere, whereby the room condition then presented can be an undesirable one in the light of efficient raising of chickens.
A next subject to be considered in the mass-raising of poultry is concerned with lighting within the poultry house.
The closed-structure construction for raising of poultry to which the present invention pertains has no window for natural lighting, so that without a room lighting system, chickens being raised cannot see the presence of feed. Lighting within the chicken-raising house or room is usually effected by electric lamps suitably hung from the ceiling of the room, and in this connection there exists a few points to be put for consideration: If the lighting fails to evenly be made within the room as a whole, chickens tend to assemble at a brighter lighted point or points where they can better see the presence of grains or other feed, and it then is difficult to carry out an even feeding to the whole of a great number of chickens raised altogether. Further, even if the lighting itself is desirably uniform throughout the room, if the degree of lightness is excessive the chicken can see not only a closest located feeder but also other feeders located in the vicinity thereof and tends to run about from one feeder to another consuming energy.
Accordingly, it also forms an important problem in poultry raising to provide an effective room lighting system with which light can be evenly scattered towards a number of feeders in the room and chickens being raised therein can be thereby prevented from tending to exert energy consumptive running-about.
Then, ventilation is still another subject requiring discussion.
Inasmuch as the house in which chickens are raised according to the present invention comprises a substantially completely closed construction having no constantly open window, it is necessary to provide thereto a system for artificially operating ventilation, and various methods are known in this respect. One of typical examples of the known methods proposes to provide a suction opening in the side wall of one of the longitudinal ends of the closed construction and an exhaust fan to the side wall of the other end to carry out ventilation. According to another example, introduction of outdoor air into the poultry house is made through the ceiling thereof with the discharging of polluted indoor air effected by a fan disposed in a side wall. In a further example, a side wall is provided with a fresh air introduction opening, and the ceiling with an exhaust fan. It also is known to introduce outdoor air through a duct up to the ceiling of the house and effect discharging of polluted air through an exhaust fan provided to a side wall.
Each of those known methods requires the provision of an exhaust fan in the house and cannot avoid the generation of noise due to the operation of the fan and its associated motor. In addition, it is difficult with such known methods to fulfil a regular or uniform ventilation across the whole of the house.
Chickens are highly sensitive to machine noise, and particularly when the fan is put for operation or its rotation velocity is put for a change, they become so excited as to commence running or jumping and, consuming their energy, lower their appetite. Use of an exhaust fan in the housing for poultry farming is disadvantageous also in that it is prone to induce a high wind condition in the house, which is again detrimental to sound or efficient growth of chickens.
It is generally accepted that the required volume of ventilation per chicken (2 Kg in weight) is on the order of 0.28 m.sup.3 /min., then required is a fairly great ventilation capacity.
With the existing constructions for raising of poultry therein, they normally have such a structure in which the wall member is formed with a constantly open ventilation opening provided in most cases with a wire net covering. Even when ventilation is scarcely required as in winter for example, this structure permits cold outdoor wind to blow into the room to let the temperature control within the room become difficult. In often cases, ventilation openings of the above structure allows entry of insects and even rats or the like into the room. Moreover, whereas the atmosphere within the poultry raising room normally is more or less dusty with barbs and downs of fallen feather and so forth, a forcible ventilation relied on exhaust fans, if operated under such room condition, will readily stir up small fragments or fallen feather, which will become attached onto the members of the fan, to result in lowering of the ventilation efficiency and more of vibration and noise. Also, whereas according to the current system of ventilation it usually is operated to take outdoor air directly into the room, this manner of ventilation can adversely affect the room warming efficiency particularly in winter in cold districts.
Consequently, it also has been an important problem in the art of poultry farming to materialize an improvement which enables ventilation of the construction for chicken raising to be done at a high efficiency, with an enhanced regularity or evenness and at a suppressed noise generation.
Then, in the case of keeping or, more particularly, raising of pigs, except the lighting for the raising house that will not involve a particularly serious problem in this case, a same may be considered as considered above in connection with the instance of chicken raising, provided that the demand for an improvement particularly relating to the ventilation has been stronger in this case than in the case of chicken raising, in reflection of the difference in the waste pigs and chickens respectively discharge.